A class of machines exists in the art generally known as “scroll” machines for the displacement of various types of fluids. Such machines may be configured as an expander, a displacement engine, a pump, a compressor, etc., and the features of the present invention are applicable to any one of these machines. For purposes of illustration, however, the disclosed embodiments are in the form of a hermetic refrigerant compressor.
Generally speaking, a scroll machine comprises two spiral scroll wraps of similar configuration, each mounted on a separate end plate to define a scroll member. The two scroll members are interfitted together with one of the scroll wraps being rotationally displaced 180° from the other. The machine operates by orbiting one scroll member (the “orbiting scroll”) with respect to the other scroll member (the “fixed scroll” or “non-orbiting scroll”) to make moving line contacts between the flanks of the respective wraps, defining moving isolated crescent-shaped pockets of fluid. The spirals are commonly formed as involutes of a circle, and ideally there is no relative rotation between the scroll members during operation; i.e., the motion is purely curvilinear translation (i.e., no rotation of any line in the body). The fluid pockets carry the fluid to be handled from a first zone in the scroll machine where a fluid inlet is provided, to a second zone in the machine where a fluid outlet is provided. The volume of a sealed pocket changes as it moves from the first zone to the second zone. At any one instant in time there will be at least one pair of sealed pockets; and where there are several pairs of sealed pockets at one time, each pair will have different volumes. In a compressor, the second zone is at a higher pressure than the first zone and is physically located centrally in the machine, the first zone being located at the outer periphery of the machine.
A compressor may include a housing, a compression mechanism, and a seal assembly. The housing may include a suction pressure region operating at a suction pressure and a first discharge passage in communication with a discharge pressure region operating at a discharge pressure. The compression mechanism may be supported within the housing and may include first and second scroll members meshingly engaged with one another to form a series of compression pockets. The first scroll member may include a second discharge passage in communication with the first discharge passage. The seal assembly may be sealingly engaged with the housing and the compression mechanism to provide sealed communication between the first and second discharge passages. The seal assembly and the compression mechanism may define a chamber in communication with one of the compression pockets. The seal assembly may include a seal member engaged with the compression mechanism and including a leg having an opening therein. The leg may isolate the chamber from the discharge pressure region when in a first position and may provide communication between the chamber and the discharge pressure region through the opening when in a second position different than the first position.
The opening in the leg may include a notch in a first end of the leg that is in communication with the discharge pressure region and isolated from the chamber when the leg is in the first position. The notch may be in communication with the discharge pressure region and the chamber when the leg is in the second position.
A compressor may include a housing, a compression mechanism, and a sealing assembly. The housing may include a first pressure region operating at a first pressure and a first discharge passage in communication with a discharge pressure region operating at a discharge pressure. The compression mechanism may be supported within the housing and may include non-orbiting and orbiting scroll members meshingly engaged with one another to form a series of compression pockets. The non-orbiting scroll member may include a second discharge passage in communication with the first discharge passage. The seal assembly that may be sealingly engaged with the housing and the non-orbiting scroll member to provides sealed communication between the first and second discharge passages, the seal assembly may include a seal member engaged with the non-orbiting scroll member and including a leg having an opening therein. The leg may provide sealed communication between the first and second discharge passages when in a first position and may provide communication between the first pressure region and the discharge pressure region through the opening when in a second position different than the first position.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.